Rensselaer Union, Volume 8, Number 9, Rensselaer, Jasper County, 18 November 1875 — Insects Destroyed by Vegetables. [ARTICLE]

Insects Destroyed by Vegetables.

To a pane of the window before which we write there is fastened a dead fly, which lies with legs sprawled wildly, with head bent away, the proboscis thrust out, and the wings standing np unnaturally. It has the appearance of haring suffered a miserable death—its members being twisted and contorted as though with spasms of pain. Examining its body closely, we discover that a white mold is growing luxuriantly between the rings of the abdomen and on the surface of the wings, and that joints of the plant have fallen off upon the window-glass, covering a space surrounding the insect of nearly an meh in length and a half-inch in width. What is the meaning of these odd circumstances, and what brought the poor fly to its violent death?

It is a clear case of murder. The fly was consumed by a vegetable, a fUngus that ate out its vital organs, and is now fattening on its remains. The fungus is called Amptwa Ifusea, and is in the habit of attacking house-flies in autumn. The germs of the plant floating in the air, or lurking in places visited by the insect, settle upon its body, and, finding congenial soil, take root and develop rapidly. The wretched victim, helplessly yielding to tlie drain on its vitality, becomes sluggish, and, when at last it'is exhausted and overcome, fixes itself to some object, and, incapable of further action, perishes. Instances are often seen like the one just described, where the fly settles on a win-dow-pane, and there succumbs to the eannibal feeding, on its vitals. “The whole of the interior organs of the abdomen,” says a writer in Nature, “ are consumed by the plant—nothing remaining but the chitinous envelope, on which the mycelia (filaments) of the fungus form a felt-like layer; the fructification showing itself externally as filaments protruding from between the rings of the body.” But the house-fly is not the only insect that is subject to tlie deadly attacks of the Ernpuea. The single order of insects that at present seems to be exempt from the ravages of any of the numerous species of this fungus is the Neuroptera, which contains tlie dragon-flies, etc. The plants have been found growing (either on the ■larva or the perfect insect) on bees, ants, beetles, butterflies, moths, gnats, crickets, aphides (plant-lice) and water-insects. In some seasons the house-fly is destroyed in vast numbers by the parasites; and the dung-fly has in certain localities been nearly annihilated by it. In the forests of Pomerania and Posen the caterpillars, which work immense destruction among the trees, have been held in check by a ftingus which has killed such numbers as really to save the forests from threatened extermination. In certain seasons these caterpillars appear to suffer as from an epidemic; their bodies swell to bursting, and white threads of mold issue from them incircles between the rings. In this condition multitudes are found still clinging to the leaves on l ' which they were feeding. The species of fungus which thus proves a benefactor to tlie "forester of Northern Germany has been named by Dr. Reichhardt, of Vienna, tlie Empusa aulica.

There is a species of wasp in the West Indies that is commonly infested with a destructive fungus. It' is supposed that the germs of the plant find access to the interior of the wasp’s bodj- through the breathing pores at the side. Here they develop m luxurious vegetation, sending out their delicate joints through the surface. Individuals have been seen with plants as long as themselves projecting from different portions of their bodies. Very literally the tormented creatures dwelt under the shadow of their own vine and fig-tree; but the shadow was in the last degree baneful. The breath of the Upas is not more deadly. In time the fungus growth spreads through the body and extinguishes the life of the insect. After this the plant thrives more luxuriantly than ever—the decomposing tissue of tlie dead Laxly serving to afford it more favorable nutriment than the living structure. The particular fungus which affects the wasp is known as the Torrubia sphecocephala..

About twenty-five species of this genus are known to be parasitic on insects. Five speciis have been CTbserved in youth Carolina. one in Pennsylvania, on tlie larvae of the May-bug; and one other NorthAmerican species on nocturnal moths. One species has been noticed in Cayenne; one in Brazil, on the larva' of a Cicada (commonly called locust); and one on a species of’ant. Two species are found in the West Indies, one in New Guinea, one in Senegal, two in Australia, two in New Zealand, two in India, one in China and three in Great Britain. The destructive silk-worm disease termed muicar-diMis produced by a fungus—the botrylu baeeiana. This minute vegetable spreads through the fatty mass beneath the skin on which the worm depends as a store of nourishment when it enters the chrysalis state, and completely’ destroys the tissue. The disease is invariably fatal; but does not appear Externally until after tjie death of the insect, when it quickly projects through tlie skin. The infection is spread among the worms by particles from the i diseased {portion of a sickly individual finding their way beneath the skin of healthy worms; o'r it propagated by the

diffusion of the germs of the plant through the atmosphere. The caterpillar, chrysalis and moth of the silk-worm are liable to the disease, but it is only in the first that it occurs spontaneously. Dr. Cooke states in his treatise, on “Fungi” that, in the summer of 1826,. Prof. Seliert made a large collection of caterpillars of the moth articia tillica. for the purpose of studying their mode of growth. <On reaching their full size the insects became abnormally soft, and suddenly died. Soon after death they grew so hard and solid that if bent they Would snap in two. At the same time their bodies were covered with a beautiftil, shining white mold. On putting some of the diseased caterpillars on a tree inhabited by apparently-healthy individuals these last soon became affected like the others, and died in a similar manner. The same author relates that in the spring of 1851 from twelve to .twenty specimens of the seventeen-year locust were found, which, though still alive, “ had the posterior third of the abdominal contents converted into a dry, powdery, ochreous-yellow. compact mass of eporu-loid-bodies. The outer coverings of that portion of the insect were loose and easily detached, leaving the fungoid matter in the form of a cone affixed by its base to the unaffected part of the abdomen of the insect.” It is quite possible,,says Dr. LqAjy, that the fungus may attack the laiva or grub, develop its filaments, and produce its spores or fruit within the living chrysalis and yet not destroy the organs immediately essential to life. In this case the chrysalids might undergo their metamorphoses into perfect insects and present the appearance exhibited by these locusts.

A still more interesting example of the work of a fungus upon the body of an insect is cited by Dr. Cooke. The specimen, a cricket, was found under a log in a wood near Newark, Del: “The insect was seen standing very quietly at the mouth oi its oval cell, which is formed in the earth, having a short curved tube to the surface. Upon taking it up it exhibited no signs of movement, though perfectly fresh and lifelike in appearance. On examining it next morning it still presented no signs of life. Every part of the insect was perfect, not even the antennae being broken. Upon feeling it it was very hard and resistant, and, on making an incision through the thorax it exhaled a fungoid odor. The insect had been invaded by a parasitic fungus which everywhere filled the animal, occupying the position of all the soft tissue ana extending even to the? tarsal joints. It formeda yellowish or cream-colored, compact mass.”

Fungoid growths have been discovered on spiders and thousand-legged worms, in the eggs oi toads and frogs and on the skins of fish. Goldfish are very liable to attack from this enemy, which generally proves destructive. By changing the water constantly where the fish are kept the fungus may be extirpated, but usually it finishes its deadly work in a few weeks. But the most curious instance of a fungus flourishing on the living tissues of an animal has been remarked in several of the United States, as Virginia, lowa and Missouri. The insect affected is the larva of the moth Hepialus, commonly called the white grub. It is often very injurious to growing corn and other grains and is well known to farmers in most parts of the country. The grub descends into the earth when it has reached maturity and there passes into the chrysalis state.

Frequently, however, while still above ground spores of a species of mushroom alight upon the insect and take root within the body. As the grub goes down into the soil it bears with it the parasitic plant, which now develops rapidly, consuming the entire inner substance of the animal, and replacing this with its own vegetable tissue. Multitudes of the grubs have been turned up with tlie plow in different places, showing the plant in various stages of growth. The queerest part of all is that after the insect has been completely eviscerated it retains its original shape and size, thereby presenting the strange anomaly of a vegetable worm. In color, consistency and smell it is a mushroom; while in form and feature it is a worm. In lowa a specimen of this grub was sent to the editor of the American Entomologiet for examination that had two sprouts growing out of its head, one an inch in length, and the other one-tenth as long. Many specimens were disinterred along with this, and in all sprouts were issuing frem the same part of the body. When these parasites grow undisturbed they develop into an edible mushroom. In China, where two species of this peculiar fungus occur, they are brought to market in little bundles of eight, and •their vermicular origin and aspect detract nothing from their "popularity with the Celestials, who esteem them particularly as a dressing fob roast duck.— Chicago Tribune.